It is most desirable, when filling a tooth cavity with a filling material, such as a polymerizable dental restorative, to ensure good adhesion between the tooth surrounding the cavity and the set (polymerized) filling material since there is thereby obtained a good seal between the set filling material and the tooth which prevents, or at least markedly inhibits, ingress of mouth fluids and bacteria into the filled cavity and thus prevents further decay or loss of the filling material. In order to achieve good adhesion between the filling material and the tooth tissues, enamel or dentin, it has been recommended to provide a primer or adhesive bonding layer intermediate to the filling material and surfaces of a prepared tooth. The filling material is normally an amalgam or non-amalgam materials for direct or indirect restorations.
The priming compositions heretofore known in the art, require the separate steps of applying a priming material to a prepared dental surface, followed by the application of a dental adhesive. Such a method is described for example, in U.S. Pat. No. 5,595,487 and in U.S. Pat. No. 5,554,030. In practice, it has been found that such multi-step procedures are laborious and time consuming. The dental clinician requires time effective procedures. Hence, use of these procedures has been undesirable.
A need exists therefore, for a dental composition which will simultaneously provide a priming and adhesive material intermediate to the prepared dental surface and the subsequently applied restorative material in both direct and indirect dental procedures. By “direct” it is meant a dental procedure where a tooth is prepared to receive a dental restorative composition which is formed and hardened in place. An “indirect” procedure is one wherein a dental construct such as an inlay, only, bridge, crown or the like is first prepared and then set into the prepared and adhesive-coated tooth.